Microsoft to preview two Silverlight 4 features

Microsoft is slated to show off two features that it is incorporating into the next version of Silverlight, its Internet Explorer browser-plug-in alternative to Adobe Flash at the International Broadcasting Conference (IBC) in Amsterdam, which kicks off on September 11.

According to a September 8 press release, Microsoft plans to add a native multicast capability, as well as support for offline digital rights management (DRM). Microsoft's PlayReady DRM will work outside the browser with Silverlight 4. (Microsoft first added out-of-browser support to Silverlight with version 3, the final version of which Microsoft released to the Web in July.)

Offline DRM will allow consumers to download a movie and watch it later when they're offline, even if it is DRM-protected. Microsoft also is touting the out-of-the-browser capability as allowing movie studios to offer network-delivered updates, special offers, live events and other experiences that will "extend their relationship with consumers past the single movie purchase."

Microsoft officials declined to share any target dates as to when the company is planning to deliver a test build or final version of Silverlight 4. There is a growing Silverlight 4 wish list on Microsoft's Silverlight site, however.

Microsoft also announced on September 8 plans to release its Internet Information Services (IIS) Smooth Streaming Transport Protocol and Protected Interoperable File Format (PIFF) specification under the Microsoft Community Promise. By doing this, Microsoft is trying to encourage third-party developers to build client-side software and services that interoperate with Smooth Streaming. The Microsoft Community Promise is a Microsoft agreement not to sue developers for patent infringement for a specific technology.